Chuck



Filed May 23, 1945 2 Sheets-Sheet 1 March 29, 1949. c, J, FRETTQLQSO 2,465,366

CHUCK INVENTOR. (arm 0e J fieffo/oso L 3 .5 52- 5 WW' ATTORNEY March 29, 1949. c. J. FRETTOLOSO 2,455,366

cnucx v Filed May 25, 1945. 2 Sheets-Sheet 2 4 INVENTOR. Gimme J Freffo/oso ATTORNEY Patented Mar. 29, 1949 illaims.

(Granted under the act of March 3, 1883, as amended April 30, 1928; 370 0. G. 757) This invention relates to improvements in chucks for holding piston rings during th milling operation necessary for the making of oildrain slots.

The primary object of this invention is to provide a chuck that is adjustable readily to fit any size piston ring.

Another object is to provide a chuck that is adjustable .to fit any size piston ring and hold thering in position rigidly for slotting.

Further objects and advantages of this invention, as well as its construction, arrangement and operation, will be apparent from the following description. and claims in connection with the accompanying drawings, in which Fig. 1 is a side view of an assembled chuck, omitting the clamping disc and with a portion in vertical section, the extreme outward position of the clamping sectors being shown by phantom lines;

Fig. 2 is a plan view of the base plate, as viewed from the right in Fig. 1;

Fig. 3 is an elevational view of the base plate;

Fig. 4 is a plan view of the assembly as viewed from the right in Fig. l, the extreme outward position of the clamping segments being shown by phantom lines;

Fig. 5 is an elevational View of a clamping sector;

Fig. 6 is a fragmentary view of a clamping sector, taken in vertical section along the line B--6 of Fig- Fig. 7 is a fragmentary view taken along line 'I-I of Fig. 4, showing the function of one of the springs; 1

Fig. 8 is a plan View of the clam-ping disc;

Fig. 9 is a side view in elevation of the clamping disc; and

Fig. 10 is an isometric view of the finished piston ring.

Similar numerals refer to similar parts throughout the several views. Clamping sectors III, movable toward and away from their common center, are mounted on base plat II.

Each clamping sector Ill has a series of armate ridges I2, which form broken concentric circles.

Ridges I2 protrude only a short distance from the clamping sectors II] to allow the use of a milling cutter axially outwardly of the ridges I2 as viewed in Fig. 1 as well as between the ridges I2. Index marks I3 are provided on the ridges I2 on one radius for proper positioning of the piston ring I4. This is accomplished when gap I5 of piston ring I4 is closed at the index mark I3,

2. it being understood that the indexing devic on the milling machine for spacing the slots I6 accurately and evenly is set up for its function from the index mark I3.

Each area between ridges is stepped as shown at ll, it, It and 28 to provide clearance for the milling cutter.

The clamping sectors H] are attached to the base plate II by means of washers 2I, which are forced against ledges 22 on the elongated slots 23 by means of screws 24 received in the base plate I I. It is to be noted that slots 23 are cut through the tongues 25 of the clamping sectors I8.

Sliding engagement between the clamping sectors I8 and base plate II is achieved by means of tongues 25 integral with clamping sectors It, which tongues are received in grooves 26 in base plate I I.

The chuck in its entirety is mounted on mandrel 2i, which has a shank 28, a threaded cylindrical section 29, a conical section 30, and a threaded stud 3 I.

Base plate II comprises an apertured disc 32 mounted on a threaded integral collar 33, which :V is bored at 42 for the reception of locking bolt Expansion of the clamping sectors I0 achieved by rotating the collar 33 on the mandrel 2? and causing the cone to force the clamping sectors I0 to the desired expanded position. It will be noted that each clamping sector It] is beveled at 35 for this purpose. After proper positioning of the clamping sector I0, screws 24 and bolt 36 are tightened to secure the clamping sectors Iil and the device as a whole on the mandrel 21.

Added support for the piston ring I4 is afforded by screwing face plate 3-6 on stud 3| by means of nut 3'! integral with the face plate 36.

Upon completion of the slotting operation, the clamping sectors I0 are retracted readily by means of tension springs 38 in wells 39 of the base plate II. The springs 38 are attached at one end to pins t0 fixed in the wells 39 and at their other ends are attached to the pins 4 I, which are fixed .to the inner faces of the clamping sectors Ill.

In the operation of the device, the assembled chuck is rotated, causing the clamping sectors It to move outwardly. The piston ring I4 is then placed within the desired series of ridges I2 and the chuck rotated in the reverse direction until the piston rin it fits snugly within the selected ridges l2, and the opening 55 is closed at index mark I3. Screws 24 are tightened to hold the clamping sectors ID in place and clamping disc 36 is threaded on stud 3| to hold the piston ring l4 securely in place. The milling cutter is then inserted between the clamping sectors In and clamping disc 36 to cut the slots 16 in piston ring I4.

While a chuck with four clamping sectors is illustrated, it is to be understood that a chuck with any number of such sectors can be employed.

Various modifications and changes can be made in the subject device without departing from the scope of the invention.

The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties, thereon or therefor.

I claim:

1. A chuck assembly comprising a mandrel,- said mandrel having a threaded portion, a conical portion adjacent to said threaded portion, and a stud adjacent to s id conical portion, a split collar in threaded engagement with said threaded portion, a generally disc shaped plate on said collar, wells in said plate, tension springs in said wells and attached thereto, radial grooves in said plate, sector-shaped plates, each of said sectorshaped plates having a tongue located in each of said grooves, the smaller ends of said sectorshaped plates being in contact with said conical portion, the faces of said sector-shaped plates having arcuate ridges for holding the work, radial slots in said sector-shaped plates extending through said tongues, a ledge about the bottom of each of said slots, a washer on each of said ledges, a screw passing through each of said washers and into each of the grooves of said plate, the portions of said sector-shaped plates between said ridges being stepped, means to attach each of said springs to each of said sector-shaped plates, a clamping plate in threaded engagement with said stud, and a clamping bolt on said split collar.

2. A chuck comprising a base, radial channels in said base at right angles to each other, wells in said base parallel to said channels, tapped holes in said channels, four sector-shaped clamping devices, said clamping devices having tongues fitting in said channels, slots in said tongues and clamping devices, and fasteners in engagement 5 a stud adjacent to said conical portion, a collar mounted on said threaded portion, means to secure said collar in selected position thereon, a base plate provided with a plurality of radial grooves and carried by said collar, a plurality of sector-shaped plates each having a tongue engaged slidably in one of said grooves, the converged ends of said sectorshaped plates abutting said conical portions and the faces thereof being stepped and having arcuate ridges on selected steps, radial slots in said sector-shaped plates extendin through said tongues, means to secure said sector-shaped plates to said base plate, resilient means to retract said sector-shaped plates, and a clamping plate in threaded engagement with said stud.

4. A chuck comprising a base, a plurality of radial channels in said base, wells in said base parallel to said channels, tapped holes in said channels, a plurality of sector-shaped clamping devices, said clamping devices having tongues fitting in said channels, slots in said tongues and said clamping devices, fasteners in engagement with said clamping device's and passin through said tongue slots and tapped holes, springs in said wells connected to said base and to said clamping devices, and means to move said clamping devices radially.

5. A chuck comprising a base, radial channels in said base at right angles to each other, wells in said base parallel to said channels, tapped holes in said channels, a plurality of sector-shaped clamping devices, said clamping devices having tongues fitting in said channels, slots in said tongues and clampin devices, and fasteners in engagement with said clamping devices and passing through said tongue slots and tapped holes, springs in said wells connected to said base and means to move said clamping devices radially.

CARMINE J. FRETTOLOSO.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 357,437 Westcott Feb. 8, 1887 803,812 Davidson Nov. '7, 1905 1,161,490 McKinney Nov. 23, 1915 1,359,992 Hook Nov. 23, 1920 1,527,866 Hall Feb. 24, 1925 FOREIGN PATENTS Number Country Date 3,414 Great Britain May 20, 1908 

